What it measures
The amount of calcium in the liquid part of the blood. About half of it is bound to proteins, mainly albumin, so labs often also report an adjusted result that allows for the albumin level.
Why people test it
- Part of a bone profile, used to check the body's calcium balance.
- Measured when looking into the parathyroid glands, which control calcium levels.
- Monitored in people with kidney disease or taking vitamin D on prescription.
Typical range
Ranges vary by lab, method, age and sex, and your report shows the lab's own range. One NHS trust gives 2.20 to 2.60 mmol/L for people aged 16 and over. Source: University Hospitals of North Midlands NHS Trust: Calcium.
Finger-prick or vein?
A vein draw is the more common route, though some providers offer finger-prick kits. Albumin is measured in the same sample so the result can be adjusted.
